code: def test_windbarbs_from_uv(self):
      x = np.linspace(-1, 1, 4)
      X, Y = np.meshgrid(x, x)
      U, V = 10 * X, 2 * Y
  
      angle = np.pi / 2 - np.arctan2(-V, -U)
      mag = np.hypot(U, V)
  
      gv_barbs = WindBarbs((X, Y, angle, mag))
      gv_barbs_uv = WindBarbs.from_uv((X, Y, U, V))
  
      np.testing.assert_almost_equal(
          gv_barbs.data["Angle"].T.flatten(), gv_barbs_uv.data["Angle"]
      )
      np.testing.assert_almost_equal(
          gv_barbs.data["Magnitude"].T.flatten(),
          gv_barbs_uv.data["Magnitude"],
      )
  
file_path: geoviews/geoviews/tests/plotting/mpl/test_chart.py
imports: import numpy
  import xarray
  import geoviews
  from geoviews.element import WindBarbs
  from holoviews.tests.plotting.utils import ParamLogStream
  from geoviews import Store
  from test_plot import TestMPLPlot
label_desc: Use image node_id 3 for calling the TestWindBarbsPlot obj's underlying member method code with example usage: obj.test_windbarbs_from_uv() without return types